The invention relates to a mixing and dispensing machine and more specifically a machine used for the preparation of frozen dairy products and ice mixed beverages.
In the past refrigerated mixing and dispensing machines were bulky due to the fact that the drive train for the machine was offset from the drive shaft of the motor. These drive trains usually utilized drive belts which results in power loss, slipping and inefficient use of space.
Since many prior refrigerated mixing and dispensing machines have the mix gravity fed to the dasher assembly, there is resulting erratic performance of the machines. When equipped with a pump, existing refrigerated mixing and dispensing machines are often not easy to disassemble and clean.
Another existing problem for prior refrigerated mixing and dispensing machines is the inability of the the dasher blade assembly to keep the mix from freezing on the interior walls of the freezing cylinder thereby causing inefficient heat transfer. Most of these machines have fixed blades that maintain a constant pressure and present wear problems. Other tensioning means employ complicated spring mechanisms, or fluid pressure seals.
A further problem to be improved upon is the dispensing assembly of the present day machines. Most of them have excessive play in the inner face union. Also most of the handles are made of more than one piece.
One object of the invention has been to create a gearmotor driven, over the shaft, clutch assembly, configuration option design to provide an inexpensive, short coupled torque adjustable structure for disengaging the drive linkage. The clutch has been designed to contain a receptor fitted to receive a flexible coupler. Such a device shortens the drive-line and eliminates the problems associated with offset belt drives, namely power loss, slippage and inefficient use of space.
Another object of the invention is to produce an offset mount, clutch driven, rotary pump to transport fluid/air mixtures from the mix tank to the dasher cylinder. The pump has been designed to utilize plunger gravity or a combination of gravity and spring tension to adjust bypass volume, which in turn controls delivery pressures without the use of additional valve structure in return lines. This simple two piece pump insures constant delivery and eliminates the erratic performance of gravity fed machines. It is also easier to disassemble and clean than existing gear pump assemblies.
A further object of the invention has been to construct a sleeve type metering valve designed to regulate the ratio of air to fluid at the pump intake. Fitted to the pump body, the assembly also functions to house the gravity stem of the pump plunger and the optional plunger tensioning spring. The design requirements specify a continum of air infusion settings, provisioned for adjustment of bypass pressures, and complete disassembly for convenient cleaning. This unit would replace the standard gravity fed carburetor tubes that fail to fill or properly regulate mix ratios.
An additional object of the invention has been to design a dasher assembly that will effectively fold the mix against the cylinder freezing wall, move the mix forward toward the dispensing orifice, and keep the interior walls of the freezing cylinder clean to insure efficient heat transfer. The later function has been particularly troublesome. Fixed blade machines maintain constant pressure and present wear problems. Other tensioning means employ complicated spring mechanisms. A primary design objective of the present invention was to develop a novel torque regulated tensioning structure that would sense the consistency of the mix and adjust the blade wiping pressure accordingly. In the present invention, torque from the lateral surface of the pump is utilized to pressure load the scraper blade against the cylinder wall in proportion to the torque required to rotate the dasher, a variable that is determined by the viscosity of the mix. Other maintenance objectives require the scraper blade be wear compensating and inexpensive to replace.
A final object of the invention has been to develop a dispensing assembly of a simple design that would feature a piston type of valve in ball and socket engagement with a leveraged handle. The engagement was sought to minimize play in the innerface union, but would require a reciprocating fulcrum. An object of the invention was to design a tracking structure that would support that requirement. A further object of the design was to develop a one piece handle with fixed pin fulcrum that could be front loaded to its operating position. A removable dispensing cup would be required to limit sleeve travel, and variations in cup orifice would be essential to accommodate desired changes in the volume and shape of the product.